This invention relates to a method and apparatus for segmenting a field of view and, in particular, to a method and apparatus for developing sub-fields of the field of view.
To facilitate recording and reproduction of images in formats which require resolution beyond the capabilities of a single camera target, composite camera systems have been proposed in which the field of view is divided or segmented into sub-fields each of which is received by one of multiple camera targets and recorded. To display the recorded image, the sub-field images are projected simultaneously in their appropriate relationship. Since the target used to record each sub-field has the same resolution as the target normally used for the entire camera field of view, the resolution of the displayed image of the sub-fields will be increased in dependence on the number of sub-fields used. As a result, a desired increase in resolution of the reproduced image can be achieved.
In order for the above camera systems to be free of undue degradation, the developed sub-fields must be contiguous and non-overlapping. This can be achieved by designing the system so that the sub-fields have a common focal point. A system designed in this manner which develops sub-fields both horizontally and vertically is disclosed in Goldsmith U.S. Pat. No. 2,219,149.
In the Goldsmith system, the field of view is conveyed by the system lens to a first mirror arrangement which segments the field of view horizontally into two contiguous, non-overlapping sub-fields. Each sub-field is then directed to its own lens/mirror arrangement which segments the respective sub-field vertically to develop two smaller, contiguous, non-overlapping sub-fields. The overall result of the arrangement is thus the production of four sub-fields which are contiguous and non-overlapping in both the horizontal and vertical direction.
The Judd et al. U.S. Pat. No. 4,890,314 also discloses a system in which contiguous, non-overlapping sub-fields are developed. In the disclosed embodiments in Judd, the sub-fields are produced only in the horizontal direction.
The Goldsmith and Judd systems are disadvantageous in a number of respects. Thus, the Goldsmith system is not compact because the system requires multiple mirror arrangements to segment the field of view horizontally and then vertically. The Judd embodiments on the other hand, only provide horizontal sub-fields and not both horizontal and vertical sub-fields.
It is therefore an object of the present invention to provide an improved apparatus and method for segmenting a field of view into contiguous, non-overlapping vertical and horizontal sub-fields.
It is a further object of the present invention to provide a camera system incorporating the apparatus and method described in the previous objective and to further provide a high definition television (HDTV) system utilizing the camera system.